Cushion body structure of a car seat

ABSTRACT

A cushion body (10) for forming a car seat, which facilitates attachment of a skin material (15) to a cushion material (11). 
     The cushion body (10) is made by attaching a planar fastening body (12) in a cushion material molding die (20) and unifying with the cushion material (11) along a three-dimensional curved surface shape of an interior surface of the die by an internal foamed molding pressure of the cushion material (11). The planar fastening body (12) is made of a planar fastening material (13) connecting with a supporting material (14) which is basically the same composition as the cushion material (11).

TECHNICAL FIELD

The present invention relates to a cushion body for an automobile seatand, in particular, relates to a cushion body of an automobile seat towhich a surface material is attached through a fastener member fixedconformably on a three-dimensional curved surface of a cushioningmaterial forming the cushion body.

BACKGROUND OF THE ART

Several methods for fixing a surface material on a surface of acushioning material which is made of a foamed body and is a main part ofan automobile seat have been known and used in public. In the prior art,in order to fix a surface material on a cushioning material having aconcave surface shape about the center thereof, a back side surface ofthe surface material was bonded on a surface of the cushioning material,or a surface material was fixed on a cushioning material by pouringurethane in a mold after setting the surface material therein. However,in such methods for fixing or bonding a surface material on a cushioningmaterial, their own production systems are required, and it is difficultto install such systems in a continuous assembly line. Thus, the costfor installing the system is increased. Also, because automobile seatsare made by mass production, it is required to maintain highproductivity because a lower volume results in a rise in cost.

In order to avoid such disadvantages, a flat fastening material is usedfor attaching a surface material on a cushioning material. This flatfastening material is called a flat fastener or flat fastener material.The fastener is made of tufting many hooked or ring-shaped smallprotrusions on a base sheet of the fastener. The hooked or ring-shapedsmall protrusions can hook and mechanically attach to a fabric whichforms the back side of the surface material. It is found that since thesurface material can be easily separated away from the fastener, whilethe surface material cannot be moved in a direction parallel to thefastener, such a fastener material as means for attaching a surfacematerial on a cushion body is relatively superior.

Since this flat fastener material is basically a two-dimensional planarshape, if a seating part of a seat has a relatively flat planar shape,such a flat fastener material can be adhered to a flat surface of theseating part, and a surface material can be attached to the seat throughthe flat fastener material by pressurizing the flat fastener materialthereon. However, if a seating part of a seat has a three-dimensionalcurved shape, it is difficult to conformably adhere such a flat fastenermaterial to a three-dimensional curved surface of a cushioning material.

Therefore, an object of the present invention is to provide a cushionbody of an automobile seat in which a flat fastener material is fixedconformably to a seating part of the seat having a three-dimensionalcurved surface shape.

DISCLOSURE OF THE INVENTION

For this, the present invention provides a cushion body consisting of acushioning material having a three-dimensional curved surface and afastener body consisting of a supporting material layer and a fastenermaterial bonded thereon, wherein the fastener body is fixed on thecushioning material by positioning the flat fastener body in a mold forshaping the cushioning material along a three-dimensional curved shapeof the mold and then pouring a liquefied foamable composition in themold to form and shape the cushioning material in the mold. The fastenerbody is basically the same material as the cushioning material.

To fix the fastener material on the supporting material layer, anadhesive may be used. Alternatively, it may be done by setting thefastener material in a mold and pouring and molding a foamablecomposition forming the supporting material layer or slab in the mold sothat the fastener becomes integral with the supporting material. Whenthe cushioning material is made of urethane, it is preferable to use aurethane material (a slab) as the supporting material layer and to fixthe fastener material on the slab by lamination. The thickness of theslab, which is not specially limited, is 5-15 mm and preferably 10 mm.

Such a fastener body is attached on at least a central main part of aseating portion of the cushioning material so that the cushion body isformed. Upon placing a surface material on the fastener body andstrongly pressuring it, a fabric of a back surface of the surfacematerial is securely hooked on the fastener material so that the surfacematerial is attached on the cushion body, and thus an automobile seatmay be easily and speedily produced. According to the present invention,by pre-producing a certain number of such a cushion body with thefastener body, it is possible to rapidly and competently respond tovarious orders by covering and attaching surface materials on thecushion bodies in accordance with the amount of orders received, and itis unnecessary to provide large scaled and ineffective productionsystems such as conventional surface integral molding, and it becomeseasy to contribute to reducing the cost of the product.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view depicting an automobile seat having aseating surface having a three-dimensional curved surface shape pursuantthe present invention, and a fixation position of a fastener bodyaccording to the present invention is shown as an example by dottedlines.

FIG. 2 is a cross sectional view of a cushion body taken along a lineA--A of the seat shown in FIG. 1 with only a left hand side of a surfacematerial attaching to a fastener material being shown by a dotted line.

FIG. 3 is a sectional view of a mold forming a cushion body with afastener body consisting of a fastener material and a supportingmaterial shown in FIG. 2, and the fastener body attached to a surface ofthe mold is shown in a condition before pouring a foamable compositiontherein (by a dotted line) and is shown in a condition after foaming it(by a solid line).

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawings, a preferred embodiment of the presentinvention is described in the following description.

FIG. 1 is a perspective view describing one example of an automobileseat. The seating surface of the seat is a three-dimensional curvedsurface depicted by three lines, A--A, B--B and C--C, to express thegeometry of the curved surface. As seen by lines A--A and C--C, a frontpart of a central portion of the seating surface rises at the center (anintersection of A and C indicated by number 1) and lowered from thecenter to left and right hand sides, and a bucket-shaped seat is formedby sharply rising up at the left and right hand sides, as seen bynumbers 2 and 3.

In contrast, as seen by line B--B, the rear part of the center isdepressed at the intersection 4, and the seating surface is slightlyrising up to the left and right hand sides and is then continuouslyrising up to the side portions 5 and 6. Both heights of the sideportions 5 and 6 are smaller than the side portions 2 and 3. While aseat having such a three-dimensional curved surface formed thereon canbe fitted with a figure of a person who sits on the seat, there has notexisted a seat made by attaching a fastener material over such athree-dimensional curved surface before the present invention.

The fastener body 12 of the present invention is generally attached overthe whole width of the center portion on a seat surface having such athree-dimensional curved surface. The fastener body 12 forms thethree-dimensional curved surface together with a cushioning material(indicated by number 11 in FIG. 2), and the fastener body 12 and theside portions of the cushioning material 11 are covered with a surfacematerial (indicated by number 15 in FIG. 2).

This cushion body 10 basically consists of a cushioning material 11 anda fastener body 12. The fastener body 12 must have a predeterminedthree-dimensional curved surface and is connected with the cushioningmaterial 11.

In a preferred embodiment, the fastener body 12 to be attached to thecushioning material 11 is made by connecting the fastener material 13(preferably, a hook or protrusion type surface fastener commerciallysold by a company named KURARE Inc.) with a slab-urethane layer as asupporting material layer. Note that the fastener body 12 and thefastener material 13 are basically flat. While the fastener material 13and the slab-urethane layer 14 may be bonded by an adhesive, it ispreferable to fuse and laminate the fastener material 13 on theslab-urethane layer 14. The under surface of the slab-urethane layer 14is connected with a cushioning material 11 made of a urethane foam, andsuch a connection is done by pouring urethane composition in a mold andfoaming the composition therein. The cushion body 10 is made byconnecting the cushioning material 11 with the fastener body 12. Theseat is completed by attaching a suitable surface material 15 thereon.While the surface material 15 indicated by a dotted line covers only theleft hand side of the seat in FIG. 2, the surface material 15 is alsoreadily attached on the fastener material 13 and the cushioning material11 on the right hand side, symmetrical to the left hand side. The backsurface of the surface material 15 is attached to a plurality offasteners 13' provided on the fastener material 13, and a good fasteningforce is exhibited thereby.

In addition, a sutured part of the surface material 15 is shown asindicated by number 16 in FIG. 2. While the sutured part thereof isshown as accommodated in a gap 17 between the cushioning material 11 andthe fastener body 12, it is not necessarily so limited in thisconfiguration.

Such a cushion body 10 of the present invention is manufactured by usinga mold as shown in FIG. 3. In a lower portion 20 of the mold, the centerportion thereof is a bottom surface 21 having a predeterminedthree-dimensional curved surface. A geometry formed by the lower portion20 and an upper portion 24 of the mold shown in FIG. 3 is generallycorresponding to a section cut along line A--A of FIG. 1 and thecross-sectional view depicted in FIG. 2. Thus, while in FIG. 3 thecenter of the bottom 21 is depressed to form a deeply depressed surface(corresponding to the center portion 1 of FIG. 1) in a section alongline B--B, the center of the bottom surface 21 of the mold is, incontrast, protruded (corresponding to the center portion 4). Partitions22 are provided face-to-face at both sides of the bottom, and each tipportion of the partition 22 is bent to form hook-shaped portion 23. Thehook-shaped portions face each other and are bent inward. The fastenerbody 12 as mentioned above is set and clamped under the hook-shapedportions 23 in a state as shown by a dotted line in FIG. 3. Aftersetting the fastener body 12 in the mold in such a manner, a liquefiedfoamable composition of urethane is poured downward in the mold. Then,an upper portion 24 of the mold is put on the lower portion 20, and thecomposition is foamed in the mold. Thereafter, the fastener body 12 ispressurized onto the bottom surface 21 of the lower portion 20 of themold by the interior pressure due to expansion molding of the cushioningmaterial 11, as indicated by the solid lines in FIG. 3, and the fastenerbody 12 is integrated with a foamed urethane (the cushioning material11) along the predetermined three-dimensional curved surface of thebottom 21 of the mold. After the composition is hardened, the cushionbody 10 is removed from the mold by opening the upper portion 24 of themold. Slab-urethane 14 positioned on the end portion of the fastenerbody 12 is soft so that the fastener body 12 clamped in the partitions22 can be easily taken out therefrom, by-passing the hook-shapedportions 23.

As a preferred embodiment, a seat having a three-dimensional curvedsurface corresponding to a figure of a person who sits thereon as shownin FIGS. 1 and 2, has the fastener body 12, which consists of thefastener material 13 (of a surface fastener of KURARE) and foamedurethane foam 14 (a slab-urethane layer) as a supporting material havinga selected thickness of 5-15 mm and a density of 0.018 g/cm³ -0.040g/cm³. The suitable thickness and density depend on a feeling to sit anda required curved surface shape.

In practice, for a seat shape having 10 mm in depth of a curveddepressed surface, the fastener body 12 is made of a supporting materialof a urethane foam having a thickness of 10 mm and a density of 0.034g/cm³.

Also, it is found that a feeling to sit can be better by forming a gap17 by opening the periphery of the fastener body 10 in a range of 5-20mm from the side portion of the cushioning material 11, dependent on thedimension of the bucket of the seat.

AVAILABILITY IN INDUSTRIES

As described above, in accordance with the present invention, a fastenerbody consisting of a fastener material connected with a supportingmaterial layer, which is basically the same material as a cushioningmaterial, is fitted with an interior geometry of a mold for shaping thecushioning material and the fastener body, and a cushion body is formedby integrating the fastener body with the cushioning material along apredetermined three-dimensional curved shape by an internal pressure dueto expansion molding of the cushioning material.

That is, it is achieved by the present invention to form a fastenermaterial having a predetermined or desired three-dimensional curvedsurface. This has not been able to be achieved by the prior art.

The three-dimensional curved surface is structured by positioning thefastener body into the cushioning material so that an automobile seatusing this cushion body can provide good feeling to a person who sitsdown thereon and can provide comfort to the person, as the cushion bodyfits with the figure of the person.

The most important factor is that by embodying a cushion body with sucha fastener material, the step of attaching a surface material thereon isfacilitated, it avoids providing production equipment as used in theprior art, it enables rapid response to variation of production, andhigh-quality automobile seats can be supplied rapidly without asubstantial cost increase.

We claim:
 1. A vehicular seat cushion comprising, a cushioning materialhaving a seating surface with a center portion and rising side portionsto either side of said center portion, said center portion of saidseating surface having a three-dimensional curved surface, a fastenerbody having an under surface affixed to said center portion of saidseating surface and an upper surface duplicating said three-dimensionalcurved surface of said center portion of said seating surface, saidupper surface of said fastener body having a plurality of fastenersdisposed thereon, and a surface material covering said cushioningmaterial and attached to said plurality of fasteners, whereby saidsurface material assumes said three-dimensional curved surface of saidseating surface.
 2. A vehicular seat cushion according to claim 1,wherein said surface material has a suture at substantially the juncturebetween said rising side portions of said seating surface and saidfastener body.
 3. A vehicular seat cushion according to claim 1, whereinsaid fastener body comprises a urethane foam slab and a fastenermaterial fixed thereon.
 4. A vehicular seat cushion according to claim3, wherein said urethane foam slab and said fastener material are fixedto each other by lamination.
 5. A vehicular seat cushion according toclaim 1, wherein said fastener body includes a foam slab layer affixedto said center portion of said seating surface and a fastener materialon said upper surface carrying said plurality of fasteners.
 6. Avehicular seat cushion according to claim 5, wherein said center portionof said seating surface is a foam which is attached to said foam slab byexpansion molding.
 7. A vehicular seat cushion according to claim 5,wherein said fastener material is laminated to said foam slab layer. 8.A vehicular seat cushion according to claim 5, wherein a gap is formedbetween said rising side portions of said seating surface and saidfastener body in which a suture is positioned.